Allow removing header in default header plugin (#3791)

Co-authored-by: Opender Singh <opender94@gmail.com>
Co-authored-by: Dimitri Mitropoulos <dimitrimitropoulos@gmail.com>
Co-authored-by: Bing <zhangb@mskcc.org>
Co-authored-by: Opender Singh <opender.singh@konghq.com>

plugins/insomnia-plugin-default-headers/README.md

@@ -21,4 +21,11 @@ Headers can be added by setting a `DEFAULT_HEADERS` environment variable.
 	}
 }
 ```
-
+Default header can be removed by setting value to null. For example, use folder environment variables to remove authorization header from anonymous calls
+```json
+{
+  "DEFAULT_HEADERS": {
+    "Authorization": "null"
+  }
+}
+```

plugins/insomnia-plugin-default-headers/src/default-headers.js

@@ -12,7 +12,12 @@ module.exports = function(context) {
       continue;
     }
 
-    context.request.setHeader(name, value);
-    console.log(`[header] Set default header ${name}: ${value}`);
+    if (value==="null") {
+      context.request.removeHeader(name);
+      console.log(`[header] Remove default header ${name}`)
+    } else {
+      context.request.setHeader(name, value);
+      console.log(`[header] Set default header ${name}: ${value}`);
+    }
   }
 };